"She a respected member of Caucus ... [she has] a distinguished record of public service as the member for Sydney, and also most recently as the Minister for Health."

Ms Plibersek says she will do her best to defend Labor and push its vision for the future.

"I want to say how very conscious I am of becoming deputy. Of how I will absolutely endeavour to do my very best by my colleagues," she said.

She became emotional as she reflected on her appointment.

"I don't think there are many countries in the world where someone whose parents came here with nothing but a suitcase each can end up being a member of Parliament, let alone taking up the responsibility which my colleagues have entrusted me with. Thank you all," she said.

I want to say how very conscious I am of becoming deputy. Of how I will absolutely endeavour to do my very best by my colleagues.

Deputy Labor leader Tanya Plibersek

Ms Plibersek says Labor has three important tasks over the coming months - defending Labor's legacy, explaining the party's vision for the future and continuing to rebuild and unite the party.

"This period in opposition will be an important one for us to articulate our vision for the future and how that vision can be achieved," she said.

Prime Minister Tony Abbott says he called Mr Shorten last night to congratulate him on winning the leadership ballot.

"I've had a bit of experience being Opposition Leader. It's a great job but it's a tough job," he said.

"I know he'll do his best and I certainly respect Bill Shorten's political skills. He has a lot of political acumen."

Former prime minister Julia Gillard has tweeted her congratulations to Ms Plibersek on her appointment.